I was talking to an old classmate from high school yesterday, and she told me she had a similar experience when she first went to dinner with her husband's family. She thought they were hostile and fighting. After a few years she realized that was not the case, they just said what was on their minds. My classmate tells me that her family buried their feelings and let them stew so that a chance remark might fester for years before being drug out and used to batter the offender.
Then today I read this in Carolyn Hax's advice column (the link will want you to register):
Q: ... Any words of wisdom?It's all very well to tell the occasional little white lie to avoid hurting someones feelings, but to be forever biting your tongue can turn your insides into a stew of angry emotions. Say what you mean, mean what you say. Good advice, but sometimes hard to follow, especially if you weren't brought up that way.
A: No, just words of disgust. If she won't say what she means, then that's her problem. If you won't say what you mean, then that's your problem. If neither one of you has the nerve to say what you mean to the other, then I can see why you're so hot to get away: You're in hell.
As for my wife and I, we manage to communicate in spite of our intrinsic differences.